Electrical system



Nov. 14, 1939. L. H. VON OHLSEN 2.179.651

ELECTRICAL SYSTEM Filed Feb. 9, 1957 mil INVENTOR Louis H. Van O/zlsenATTO RN EYS Patented Nov. 14, 1939 UNITED STATES PATENT OFFICEELECTRICAL SYSTEM Application February 9, 1937, Serial No. 124,838

8 Claims.

This invention relates to electrical connecting apparatus, and, withregard to the more specific features thereof, to automatic means for theconnection and disconnection of a source of current and a storagebattery.

One of the objects thereof is to provide apparatus of the above natureof simple and thoroughly practical construction. Another object is toprovide apparatus of the above nature of eflicient and dependableaction. Another object is to provide apparatus of the above nature inwhich the opening and closing of contacts is brought about withcertainty and absence of chattering. Another object is to provideapparatus of the above nature which although ruggedly built is highlysensitive in its action. Other objects will be in part obvious and inpart pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangement of parts as will beexempliiied in the structure to be hereinafter described and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing in which is shown one of the variouspossible illustrative embodiments of this invention,

Figure 1 is a diagrammatic plan;

Figure 2 is a side elevation of a contactor and associated parts.

Similar reference characters refer to similar parts throughout bothviews of the drawing.

As conducive to a clearer understanding of certain features of thisinvention, it may be noted that in a certain use of apparatus such as isherein dealt with, the conditions of jarring and vibration are severeand the available forces for timely action are small. To provide aruggedness and simplicity of construction suitable to meet the shocksand jars to which it is exposed and yet such sensitiveness as willutilize the small vailable forces to cause timely and dependable action,is one of the dominant aims of this invention.

Referring now to Figure l of the drawing, there is shown at In agenerator which may be driven from the axle of a railway car and thussubject to stoppage and a wide variation in speed. This generator isprovided ,with the shunt field winding II and suitable regulatingapparatus diagrammatically indicated at l2. From one terminal of thegenerator the lead 13 connects to the swinging member M of a contactoradapted to make connection with a conductor l5 leading to a series c i15 f om which spring 28 and/or gravity.

the main generator current is led by a conductor I! to one of theterminals of a suitable storage battery Hi. The remaining terminal ofthe storage battery I3 is connected by conductor [9 to the remainingterminal of the generator l0. '5 Suitable leads 20 and 2| from theterminals of the battery are adapted to carry current to the load, hereindicated as lamps 23, and it is understood that a suitable lamp switch24 and lamp regulator 25 of the usual construction are 10 q employed asindicated.

Referring back to the contactor, indicated as a whole at 26, the mainarm governing the completion of the circuits is drawn toward closedposition by a coil 21 acting in opposition to This coil 21 is connectedby conductor 22 with one of the contacts 29 of a relay indicated as awhole at 10. The coacting stationary contact 3| is connected by theconductors 32 and 33 with the generator lead or main l3. The remainingterminal of the coil 21 is connected as at 34 with the main conductori9, and hence, upon the closing of the relay, coil 21 is bridged acrossthe generator. The relay 10 comprises a swinging armature 35 havingmounted thereon contact 29. This armature is pivoted at 36 and its swingis limited by the adjustable stop 31 coacting with abutment 38. Pivotedto the free end ofthe armature 35, remote from contact 29, is a movablecore 39 controlled by coils 40 and 4|. The forces tending to swing thearmature in a counterclockwise direction are due to the effect of thecoils l3 and 33 upon a fixed core 42. This core has its magnetic circuitcontinued by the members 43 and 44 so as to provide an ample magneticflux when the armature 35 is at or near closed position and enhance thecertainty of its closing action.

The coil is connected with the main con- 9 ductor l3 by means ofconductors 33 and 45. The other end of coil 40 is connected by conductor48 with the main conductor 11. Hence it will thus be seen that this coil40 is bridged about the main contacts of contactor 23 and the seriescoil l6 which is provided with the shunt 41 so as to reduce its currentflow and permit the use of a small coil.v Thus upon the closing of thecontactor 26, the coil 40 is substantially short-circuited and withoutappreciable power.

Coil 30 is connected as at 48 with the-conductor 33 and is connected-atthe other end as by 49 with the coil 4| from which the circuit is led byconductor 50 to the main conductor l9. Thus the coils 30 and 4| areconnected across the generator mains in series with each other.

A suitable resistance 5| is connected with the conductor 49 at one endand at its other end by a conductor 52 with a fixed contact 53 on thecontactor 26. Coacting with this contact 53 is another auxiliary contact54 mounted upon the conductor arm, and these contacts are so formed anddisposed as to remain in connection after the circuit between the maincontacts has been broken. In this manner when the contactor is closed, ashunt will be completed through the resistance element 5! about the coil39. This will obviously weaken the flow of current in coil 30 and yetincrease the total flow of current in conductor 49 and coil M.

Referring to Figure 2 of the drawing is a slightly more detailed showingof the-elements of contactor 26. lit will be seen that the swinging arml4, diagrammatically indicated in Figure l, is provided with a pivotaljoint 55 so that the movable main contact 56 can yield by compression ofthe spring iii. This action occurs as the contact is forced intoengagement with the coacting stationary main contact 58.

The movable auxiliary contact 54 is yieldingly mounted on a lateralextension of the swinging arm l4 by means of a side flange 59 againstwhich it is held by the coiled spring St about the pin 6| in theposition indicated in dotted lines in Figure 2. When the main arm 34swings toward closed position, the contacts 56 and 58 are forcedtogether, as are also the contacts 54 and 53. The contact 54, however,yields throughout a larger portion of its movement than the contact 56,and hence the contacts 53 and 54 will remain in engagement longer thanthe contacts 58 and 58 when the contactor opens.

A suitable balance weight 82 is mounted on the lower end of the arm I 3and serves to increase the inertia of the moving parts as well as bringtheir centerof gravity into the axis about which the swing and thusreduce the effect of jarring or vibration.

Considering now the action of this apparatus.

and assuming it to form a portion of a train lighting system, when thetrain is at a standstill the contactor 26 must be open to prevent backdischarge of the battery. At this stage the coil 40, being bridged aboutthe contacts of the contactor and coil l 8, permits back discharge tosuch an extent as will keep coil 40 alive. Although this provides aslight 'drain on the battery, this current fiow assures that thegenerator will build up with the proper polarity when it becomesreactive due to increase in train speed. This current flowing throughcoil 40 also serves to hold the relay open against shocks and jars. Anycurrent flowing through coil 4|, whether due to discharge of battery l8or the generator volt age, will assist coil) in performing thisfunction.

As the generator is started and its speed in- .creases, the currentthrough coils 30 and 4| increases and coils 4| and 40 act cumulatively.However, during this time, the rise in the generator voltage causes thebattery discharge current through coil 40 to decrease, and if thegenerator voltage exceeds the battery voltage this current will actuallyreverse. Thus, the pull of coil 3! gradually increases and thecumulative pull of coils 40 and 4| gradually decreases until theformerbecomes great enough to raise armature 35 to close contacts 29 and 3|.

Thus it is seen that coils 40 and 4| first act cumulatively, and as thegenerat r vol g 4 ually increases, the current through coil 40 decreases and actually reverses. If armature 35 remains in open position,the cumulative pull of coils 40 and 4! will decrease to zero when theeffect of the reversed current through coil 4!! equals the efl'ect ofthe current through coil 4l..

At the same time the pull of coil 30 gradually increases with theincrease of voltage. By properly designing coils 40, 4!, and till, theeffect of these three coils may be adjusted so that armature 35 will beraised to contact-closing position at any value of generator voltagenear, but above or below, battery voltage.

The closing of the circuit comprising contacts 29 and 55 leads currentdirectly through the coil 2? and the Fetter immediately swings the armid to the leit, having reference to the drawing. This action closes thecircuit, as hereinbefore described, through the series coil to and, asthe generator should then be at such voltage as to start supplyingcurrent to the battery and the load, the current may be assumed to beflowing downwardly through this coil, having reference to thediagrammatic showing in Figure 1. It thus acts cumulatively with respectto the coil 30 holding the relay closed with a force which increases asthe charging current builds up.

The closing-movement of the arm it of the contactor brings together theauxiliary contacts 53 and 54, thus closing the shunt with resistance 5|about the coil 313. The weakening of coil 30, however, and the attendantstrengthening of coil 4| are wholly insufiicient to cause opening of therelay, particularly as the coil 40 is substantially deenergized by theclosing of the main contactor.

Assuming now that the train, and hence the generator, decrease in speedand that the voltage of the latter falls, a condition is approachedwhere the generator and battery voltage are equal. At such time thecharging current passes through zero, thus deenergizing coil l6, and thecoil 30 is also weakened due to fall of the generator voltage. With thiscondition the coil 4! exerts a suflicient pull on the movable core 39 toopen the relay. This breaks the circuit of coil 21, and, the maincontacts of the contactor being separated, the coil i6 is instantlydeenergized. The coil 30, furthermore, remains weakened after theopening of the main contacts of the contactor as the movable auxiliarycontact 54 is provided with a spring mounting, as hereinbeforeexplained, which will maintain it in closed circuit position until justafter the main contacts are opened. Thus the closing eiiect of coil 30is not strengthened by the opening of its shunt until after the armature35 has moved away from coil 42. The decrease in flux due to the openingof this gap and the deenergization of coil l6 gives such a greatpreponderance of pull on the lefthand end of the relay (having referenceto Figure 1) that the latter swings open without any tendency tochattering or fluttering on its contacts.

This dependable and strong opening of ,the relay definitely terminatesthe current through coil 21 and the main contactor opens with the samecertainty and freedom from chatter.

It will thus be seen that the action of the various parts is thoroughlydependable and may be exactly timed. It will also be seen that thearrangement of coils is such that although the difference betweenbattery voltage and generator voltage may be extremely-small or evenzero, yet there are available and utilized strong magnetic forces foroperating the relay and contactor. It will also be seen that thisillustrative apparatus is adapted to achieve the objects of theinvention and to meet the hardest conditions of practical use.

As many possible embodiments may be made or the above invention and asmany changes might be made in the embodiment above set forth it is to beunderstood that all matter hereinbeiore set forth, or shown in theaccompanying drawing, is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. The combination with a generator, a battery, and a normally openswitch means for connecting said generator and said battery, ofelectromagnetic means for eilfecting closure of said switch meanscomprising a pair of independently magnetizable pole pieces, a rockablearmature mounted to be influenced by .the magnetic flux present in saidpole pieces, a first winding surrounding one of said pole piecesenergizable in accordance with the current flowing through said switchmeans, a second winding surrounding a second of said pole pieces andconnected in parallel with said switch means, a third winding mountedwith said first winding, a fourth winding mounted with said secondwinding, said third and fourth windings being connected in series acrosssaid generator, a resistance shunt, and circuit means including a switchoperative to close a connection through said shunt, said first and thirdwindings cooperating when said generator is charging said battery tohold said armature in one position and said first and third windingsopposing each other when said battery is discharging through saidgenerator, said second and fourth windings cooperating to hold saidarmature in its other position when the battery voltage is above thegenerator voltage and said second and fourth windings opposing eachother when said switch means is open and the battery voltage is belowthe generator voltage, said shunt and its switch being effective toincrease the current through said fourth winding when said switch meansis closed and to increase the current through saidsecond winding whensaid switch means is opened.

2. The combination with a generator, a battery, and a normally open mainswitch means for connecting said generator and said batteryofelectromagnetic means for effecting closure of said switch meanscomprising, a first electromagnetic unit, a second electromagnetic unit,a rockable armature mounted to be influenced by the flux of saidelectromagnetic units and thereby be moved between its two positions, acontrol switch mounted to be opened and closed by the movement of saidarmature, and a solenoid unit connected to be energized by the closingof said switch and controlling the closing of said switch means; saidfirst electromagentic unit including, a coil energizable in accordancewith the current fiowing between said battery and said generator whensaid main switch is closed, and a first generator voltage coil; saidsecond electromagnetic unit including, a shunt coil connected inparallel with said main switch, and a second generator voltage coilconnected in series with said first generator voltage coil across saidgenerator; and a shunt circuit means including a resistance unit and anauxiliary switch operative to close a connection through said resistanceunit; said shunt circuit means being effective to increase the currentthrough said first generator voltage coil when said switch means isclosed and to increase thecurrent through said second generator voltagecoil when said switch means is opened.

3. The combination with a generator, a battery, a main switch forconnecting said generator and said battery, and switch operating meansto control the opening and closing of said main switch-ofelectromagnetic means for manipulating said switch operating meanscomprising, a first electromagnetic unit including a voltage coil and acoil energizable in accordance with the current flowing between saidbattery and said generator, and a second electromagnetic unit includinga voltage coil and a shunt coil connected in parallel with said mainswitch; and a circuit means comprising, means connecting said voltagecoils in series across said generator, and a shunt circuit connected inparallel with one of said voltage coils including a resistance unit andan auxiliary switch, said shunt circuit being effective to increase thecurrent through one .of said voltage coils substantially when saidswitch is in closed position and to increase the current through theother of said voltage coils substantially when said main switch is inopen position.

4. The combination with a generator, a battery, a main switch forconnecting said generator and said battery, and switch operating meansto control the opening and closing of said main switchof electromagneticmeans for manipulating said switch operating means comprising, a firstelectromagnetic unit including a voltage coil and a coil energizable inaccordance with the current flowing between said battery and saidgenerator, and a second electromagnetic 'unitincluding a voltage coiland a shunt coil connected in parallel with said main switch; and acircuit means comprising, means connecting said voltage coils in seriesacross said generator, and a shunt circuit connected in parallel withone of said voltage coils including a resistance unit and an auxiliaryswitch, said shunt circuit being efiective to increase the currentthrough one of said voltage coils when said switch starts moving towardits closed position and to increase the current through the other ofsaid voltage coils immediately after said main switch has been opened.

5. In apparatus of the general nature of that herein described, incombination: a generator; a storage battery; a main switch to connectsaid generator to said battery; and operating means for said main switchincluding, a first voltage coil which when energized tends to cause saidmain switch to open, a second voltage coil which when energized tends tocause said circuit to close, means connecting said first and secondcoils in series, and a shunt circuit including a resistance unit and anauxiliary switch mechanically connected to operate substantially whensaid main switch operates, said shunt circuit being connected tosimultaneously strengthen one of said coils and weaken the other of saidcoils when said switch is operated.

6. In apparatus of the general nature of that herein described, incombination: a generator; a storage battery; a main switch to connectsaid generator to said battery; and operating'means for said main switchincluding, a first voltage coil which when energized tends to cause saidmain switch to open, a second voltage coil which when energized tends tocause said circuit to close, means connecting said first and secondcoils in series, and a shunt circuit including a resistance unit and anauxiliary switch mechanically connected to open immediately after saidmain switch opens and to close immediately before said main switchcloses.

7. In apparatus of the general nature of that herein described, incombination: a generator; a storage battery; a main switch to connectsaid generator to said battery; and operating means for said main switchincluding, a first voltage coil which when energized tends to cause saidmain switch to open, a second voltage coil which when energized tends tocause said circuit to close, means connecting said first and secondcoils in series, and a shunt circuit including a resistance unit and anauxiliary switch mechanically connected to open substantially when saidmain switch opens, said shunt circuit being connected to simultaneouslyincrease the current through said second coil and decrease the cur rentthrough said first coil when said auxiliary switch opens.

8. The combination with a generator, a battery, a main switch forconnecting said generator and said battery, and a control switchcontrolling the opening and closing of said main switch-ofelectromagnetic means to open and close said control switch comprising,a first solenoid assembly including a first coil which when energizedtends to open said switch, a second solenoid assembly including a secondcoil which when energized tends to close said control switch, and acircuit means connecting said first and second coils in series acrosssaid generator, said circuit means including a resistance unit and anauxiliary switch which when closed connects said shunt in parallel withsaid second coil-whereby the closing of said auxiliary switchsimultaneously strengthens said first coil and weakens said second coil.

LOUIS H. voN OHLSEN. 2o

